body,html{
  margin: 0;
  padding: 0;
}

#main{
  margin: 20px auto;
  width:260px;
}

#calc{
  margin-left: 52px;
  width: 60px;
}
input{
  margin: 5px 0;
}

span{
  color: red;
  margin-left:5px;
}

#width-validate,#height-validate{
  color: red;
  margin-left: 52px;
}
